Empirical evidence for selective reporting of outcomes in randomized trials -: Comparison of Protocols to published articles
Empirical evidence for selective reporting of outcomes in randomized trials -: Comparison of Protocols to published articles
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DOI：
10.1001/jama.291.20.2457
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发表时间：
2004-05-26
影响因子：
120.7
通讯作者：
Altman, DG
中科院分区：
文献类型：
--
作者：
Chan, AW;Hróbjartsson, A;Altman, DG
背景 人们广泛怀疑已发表的研究中基于其结果的性质或方向选择性报告结果，但这种偏见的直接证据目前仅限于病例报告。目的以实证方式研究一组随机试验中结果报告偏见的程度和性质。使用丹麦哥本哈根和腓特烈斯贝科学伦理委员会于 1994-1995 年批准的方案和已发表的随机试验报告设计队列研究。报告和未报告的试验结果的数量和特征是根据方案、期刊文章和试验者调查记录的。如果发表的荟萃分析文章中提供的数据不足，则认为结果报告不完整。计算每项试验的结果报告完整性与统计显着性之间的比值比，然后汇总以提供偏倚的总体估计。还比较了协议和已发表的文章，以确定主要结果的差异。主要结果衡量疗效和危害结果以及统计显着性与非显着性结果报告的完整性；最新方案中定义的主要结果与已发表文章中定义的主要结果之间的一致性。 结果 确定了 102 项试验，其中包含 122 篇已发表的期刊文章和 3736 个结果。总体而言，每次试验有 50% 的疗效和 65% 的危害结果未完整报告。与功效（汇总比值比，2.4；95% 置信区间 [CI]，1.4-4.0）和危害（汇总比值比，4.7；95% Cl，1.8-12.0）数据的非显着结果相比，具有统计显着性的结果被完全报告的几率更高。在将已发表的文章与方案进行比较时，62% 的试验至少有 1 项主要结局被更改、引入或省略。尽管有明确的相反证据，但 86% 的调查应答者 (42/49) 否认存在未报告的结果。结论 试验结果的报告不仅经常不完整，而且存在偏见且与方案不一致。因此，已发表的文章以及包含这些文章的评论可能不可靠，并且高估了干预措施的益处。为了确保透明度，应登记计划的试验，并在试验完成之前公开方案。
Context Selective reporting of outcomes within published studies based on the nature or direction of their results has been widely suspected, but direct evidence of such bias is currently limited to case reports.Objective To study empirically the extent and nature of outcome reporting bias in a cohort of randomized trials.Design Cohort study using protocols and published reports of randomized trials approved by the Scientific-Ethical Committees for Copenhagen and Frederiksberg, Denmark, in 1994-1995. The number and characteristics of reported and unreported trial outcomes were recorded from protocols, journal articles, and a survey of trialists. An outcome was considered incompletely reported if insufficient data were presented in the published articles for meta-analysis. Odds ratios relating the completeness of outcome reporting to statistical significance were calculated for each trial and then pooled to provide an overall estimate of bias. Protocols an published articles were also compared to identify discrepancies in primary outcomes.Main Outcome Measures Completeness of reporting of efficacy and harm outcomes and of statistically significant vs nonsignificant outcomes; consistency between primary outcomes defined in the most recent protocols and those defined in published articles.Results One hundred two trials with 122 published journal articles and 3736 outcomes were identified. Overall, 50% of efficacy and 65% of harm outcomes per trial were incompletely reported. Statistically significant outcomes had a higher odds of being fully reported compared with nonsignificant outcomes for both efficacy (pooled odds ratio, 2.4; 95% confidence interval [CI], 1.4-4.0) and harm (pooled odds ratio, 4.7; 95% Cl,1.8-12.0) data. In comparing published articles with protocols, 62% of trials had at least 1 primary outcome that was changed, introduced, or omitted. Eighty-six percent of survey responders (42/49) denied the existence of unreported outcomes despite clear evidence to the contrary.Conclusions The reporting of trial outcomes is not only frequently incomplete but also biased and inconsistent with protocols. Published articles, as well as reviews that incorporate them, may therefore be unreliable and overestimate the benefits of an intervention. To ensure transparency, planned trials should be registered and protocols should be made publicly available prior to trial completion.